Gelatin/cinnamon essential oil pickering emulsion crosslinking composite films with enhanced mechanical and antibacterial performance

High-strength and long-lasting antibacterial degradable gelatin films have attracted widespread interest recently. In the present study, genipin-crosslinked gelatin films incorporated with Pickering emulsion containing cinnamon essential oil (GPG) were fabricated by solution casting method. Results demonstrated that antibacterial GPG featuring excellent mechanical properties were successfully obtained. Fourier transform infrared spectroscopy and X-ray diffraction analyses validated a stable crosslinking network that enhanced the intermolecular forces of gelatin. The Pickering emulsions were confined within the network, averting the aggregation of particles during film formation, thus engendering a uniform and compact surface morphology. The tensile strength and fracture toughness of GPG-5 (5 wt% genipin content) have reached 20.22 +/- 2.52 MPa and 22.52 +/- 1.31 MJ/m3, representing 470.41% and 553.88% enhancements, respectively. More significantly, chemical crosslinking could further regulate the release kinetics of cinnamaldehyde, empowering the film more durable antibacterial properties. Kinetic simulations experimentally was more consistent with the first-order kinetic equation (R2= 0.9994) and proved the sustained release effect. Finally, this high -performance packaging films exhibited favorable preservation effect on the strawberries.